A loader or an unloader annexed to a workpiece-machining device conventionally comprises a traveling body that travels in the direction in which a workpiece-machining device and a workpiece-storage device are separated from each other, the traveling body having suction pads to suck the top surface of a workpiece for transfer. Such a loader and an unloader are designed to be independent of each other or to share rails for the traveling body.
The conventional loader and unloader execute loading and unloading exclusively, so both devices must be installed in order to perform both of these operations, resulting in the complicated configuration of the entire device and increased costs. Due to the use of shared parts, the loader and unloader sharing the rails for the traveling body simplifies the configuration and reduces costs compared to exclusive devices that are independent of each other, but the degree of simplification and cost reduction are insufficient.
Therefore, attempts were made to develop devices capable of loading material workpieces and unloading product workpieces using the same traveling body. Nonetheless, under a configuration in which the traveling body travels in only one direction along the direction in which the workpiece-machining device and the workpiece-storage device are separated from each other, as in the conventional loader and unloader, if the device is used for both loading and unloading, the position at which material workpieces are stored is also used as the position to which product workpieces are unloaded. Consequently, in the workpiece-storage device at which material workpieces and product workpieces are stored, a mechanism is required that can be frequently moved to move a pallet in the direction orthogonal to the direction for each material, complicating the configuration of the workpiece-storage device and increasing costs. Although the material and product housing positions can be located parallel to each other in the above direction, the resulting processing line overextends and undesirably occupies a large area of the factory.
In addition, since the conventional unloader is designed to move the traveling body in only the above direction, if product workpieces obtained by cutting a material workpiece are to be sorted depending on their type or blanking condition, a sorting device that is moved in the direction orthogonal to the above direction is required in the workpiece-storage device. This also increases costs.
Furthermore, in the conventional loader, the traveling body can be moved in only one direction, so when a material workpiece is positioned on a table of the workpiece-machining device, some of the suction pads must act as positioning pads that can be moved in diagonal directions relative to the traveling body, complicating the configuration.
An object of the present invention is to provide a workpiece-transfer device that has functions for loading and unloading workpieces without requiring the workpiece-storage device to have a function for replacing material and product workpieces with each other, and that requires only a simple configuration that entails low costs.
Another object of the present invention is to provide a square layout of the entire facility, including the workpiece-machining device and the workpiece-storage device, in order to more effectively use the floor area.
Yet another object of the present invention is to enable material workpieces to be loaded and positioned on the workpiece-machining device without requiring an exclusive positioning means such as positioning pads.